feat(triple): support generic call for Triple protocol

[Tsukikage7]

Description

This PR implements Triple protocol generic call support for dubbo-go, enabling Go clients
to invoke Java Dubbo services without pre-generated stubs and vice versa.

For detailed design documentation, please refer to: Dubbo-go Triple Generic
Call

Related PR: apache/dubbo-go-samples#1016 provides usage examples for Triple protocol
generic call.

Background

Generic call (泛化调用) is a core feature in Dubbo ecosystem that allows service invocation
without IDL/interface definitions. While dubbo-go already supports generic call for the Dubbo
protocol, Triple protocol generic call was missing, making it impossible for Go and Java
services to interoperate via Triple protocol in non-IDL mode.

Design Overview

The key challenge is that Java Dubbo Triple protocol uses a specific wire format for non-IDL
mode:

┌─────────────────────────────────────────────────────────────┐
│                    Wire Format                              │
├─────────────────────────────────────────────────────────────┤
│  Content-Type: application/proto                            │
│                                                             │
│  Request:  TripleRequestWrapper (protobuf)                  │
│            ├── serializeType: "hessian2"                    │
│            ├── args: [hessian2(arg1), hessian2(arg2), ...]  │
│            └── argTypes: ["java.lang.String", ...]          │
│                                                             │
│  Response: TripleResponseWrapper (protobuf)                 │
│            ├── serializeType: "hessian2"                    │
│            ├── data: hessian2(result)                       │
│            └── type: "org.apache.dubbo.samples.User"        │
└─────────────────────────────────────────────────────────────┘

This is a two-layer serialization: protobuf wrapper on the outside, hessian2 data on the
inside.

Implementation Details

1. New WrapperCodec Interface (codec.go)

type WrapperCodec interface {
    Codec
    WireCodecName() string  // Returns "proto" for Content-Type
}

2. New protoWrapperCodec (codec.go)

Client-side codec that wraps request arguments in TripleRequestWrapper and unwraps response
from TripleResponseWrapper.

3. Enhanced protoBinaryCodec (codec.go)

Server-side enhancement to handle incoming wrapped requests.

4. Generic Filter Enhancement (filter/generic/filter.go)

Added parameterRawValues support for Triple protocol in both isCallingToGenericService
and isMakingAGenericCall branches.

5. Server-side Generic Call Handler (protocol/triple/server.go)

Auto-registers $invoke method for Triple protocol services via buildGenericMethodInfo().

Testing

• Unit Tests: 631 lines of comprehensive tests covering protoWrapperCodec,
  protoBinaryCodec, various data types, and edge cases.
• Integration Tests: All scenarios passed (Go↔Java, Go↔Go via Triple protocol).

Compatibility

• Backward Compatible: Existing IDL-based Triple calls are not affected
• Cross-Language: Fully compatible with Java Dubbo 3.x Triple protocol
• Dubbo Protocol: Existing Dubbo protocol generic call still works as before

Checklist

• I confirm the target branch is main
• Code has passed local testing
• I have added tests that prove my fix is effective or that my feature works

[Copilot]

Pull request overview

This PR implements Triple protocol generic call support for dubbo-go, enabling Go clients to invoke Java Dubbo services without pre-generated stubs and vice versa. The implementation uses a two-layer serialization approach: protobuf wrapper on the outside (TripleRequestWrapper/TripleResponseWrapper) with hessian2-encoded data on the inside, matching Java Dubbo's wire format.

Key changes:

• Introduced WrapperCodec interface and protoWrapperCodec implementation for handling the two-layer serialization format
• Enhanced protoBinaryCodec to automatically detect and unwrap generic calls on the server side
• Added reflection-based method invocation infrastructure to support dynamic service method calls

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
protocol/triple/triple_protocol/codec.go	Adds WrapperCodec interface, protoWrapperCodec for client-side wrapping, and enhances protoBinaryCodec for server-side unwrapping
protocol/triple/triple_protocol/codec_wrapper_test.go	Comprehensive unit tests (631 lines) covering wrapper codec functionality, type mapping, and edge cases
server/server.go	Adds reflection-based method invocation support and enhances service info with $invoke method registration
protocol/triple/server.go	Refactors generic method info building and adds reflection-based MethodFunc creation
protocol/triple/client.go	Routes generic calls to $invoke method and registers it for non-IDL mode
filter/generic/filter.go	Adds parameterRawValues support for Triple protocol generic calls
protocol/triple/triple.go	Routes to NewTripleInvoker when generic call is detected
protocol/triple/triple_protocol/protocol_grpc.go	Uses getWireCodecName for correct Content-Type header
protocol/triple/triple_protocol/protocol_triple.go	Uses getWireCodecName for correct Content-Type header
common/constant/key.go	Adds protobuf and protobuf-json generic serialization constants
client/options.go	Adds WithGenericType option for specifying generic serialization type

---

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 49.10714% with 114 lines in your changes missing coverage. Please review.
✅ Project coverage is 48.07%. Comparing base (2373adf) to head (27b78d1).

Files with missing lines	Patch %	Lines
server/server.go	22.44%	33 Missing and 5 partials ⚠️
protocol/triple/server.go	57.40%	22 Missing and 1 partial ⚠️
protocol/triple/triple_protocol/codec.go	57.40%	18 Missing and 5 partials ⚠️
client/client.go	0.00%	11 Missing ⚠️
protocol/triple/client.go	41.66%	5 Missing and 2 partials ⚠️
filter/generic/filter.go	79.31%	2 Missing and 4 partials ⚠️
client/options.go	0.00%	3 Missing ⚠️
protocol/triple/triple.go	70.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3154      +/-   ##
===========================================
+ Coverage    47.81%   48.07%   +0.26%     
===========================================
  Files          460      460              
  Lines        32999    33172     +173     
===========================================
+ Hits         15779    15948     +169     
+ Misses       15952    15935      -17     
- Partials      1268     1289      +21     

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[No-SilverBullet]

LGTM :)

[Tsukikage7]

@marsevilspirit @Alanxtl Need Review pls.

[Alanxtl]

I'm wondering is this todo solved?

[Tsukikage7]

Partially. The enhanceServiceInfo function now registers both GetUser and getUser style methods, so Go and Java can find each other. But the real fix should be on dubbo-java side to handle case properly. Kept the TODO as a reminder - maybe we can push for a fix upstream later.

[AlexStocks]

建个issue，记下这个 todo 吧

[AlexStocks]

当前代码我留了一个 comment，请改进。另外，请给其中一些函数添加 unit test。

[sonarqubecloud]

Quality Gate passed

Issues
65 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
7.3% Duplication on New Code

See analysis details on SonarQube Cloud